When sending orders from your Dear Systems into Shiptheory, you are also able to specify the carrier/service you would like to use for that order. This can be used in conjunction with your Shipping Rules to allow you to automatically have that order book in based on the Shipping Method selected.
You can read more about what a Shipping Method is and how it can be used in Shiptheory from this Support Guide.
How do I add a Shipping Method to an order in my Dear?
While you are viewing an order within Dear, before you send it through to Shiptheory, you can add a Shipping Method to it.
To do this, in the Carrier / Service field, click the blue search box. This will then open a popup which will display all your available shipping services within your Shiptheory account. From this menu, choose the Shipping Method you would like to send with this order when it comes into Shiptheory.
So for the order below, the Shipping Method will be 'Address Only Labels - N/A'. 
Once Selected, send the shipment through to Shiptheory. This is done by clicking Shipping Label and then Generate Label.
Have any questions about sending this through? One of our Support Team would be happy to help!